An electronic device is known which includes a CPU (Central Processing Unit) and the like for processing various types of software. In the electronic device, a non-responsive state (hereafter referred to as a “freeze state”) may be encountered during the processing of software due to one cause or another.
The freeze state of the electronic device may be removed by pressing a reboot button. For example, a portable telephone device is disclosed in which the freeze state is removed based on a predetermined reset signal that is transmitted by pressing a predetermined button.
The above related art is discussed in Japanese Unexamined Patent Publication No. 2008-3768, for example.
However, in an in-vehicle system including an onboard electronic device, such as car navigation equipment, the freeze state cannot be appropriately removed according to the will of the user.
Specifically, in order to remove the freeze state, the part causing the freeze state, such as a navigation control part of the in-vehicle system, needs to be reset. For this resetting operation, power supply may be terminated, or a reset button may be provided and operated.
An in-vehicle system having car navigation equipment and a radio or the like includes a backup power supply (hereafter referred to as a “B/U”) directly connected to a battery and an accessory (ACC) power supply (hereafter referred to as an “ACC”) connected to the battery via an ACC terminal of an ignition switch. When the vehicle is travelling, both the ACC and the B/U are on. When the ignition switch is off (during parking, for example), the ACC is off while the B/U is on. The in-vehicle system operates when the ACC is on.
Because the freeze state occurs when the in-vehicle system is in an operating state, in order to remove the freeze state, the ACC needs to be turned off; namely, the automobile engine needs to be stopped. This demands a bothersome operation from the user, and stopping the car just so as to remove the freeze state in the middle of driving the vehicle is not a realistic solution.
Furthermore, when the ACC is turned off, not just the part causing the freeze state but also the system as a whole is reset by the turning-off of power supply, resulting in a wastefully extensive and deep resetting operation.
In the case of the resetting process involving the reset button, although a reset can be made when the automobile is travelling, this method also leads to the resetting of not just the part causing the freeze state but also the entire system by the reset button operation, resulting in a wastefully extensive and deep reset. While it is possible to provide a plurality of reset buttons corresponding to different operating states, this results in an increase in the number of reset buttons and cost disadvantage, and may also confuse the user over which one of the reset buttons to choose. Thus, this solution is also not realistic.
In view of the foregoing, there is the problem of how to realize an in-vehicle system capable of appropriately removing the freeze state of car navigation equipment on a vehicle according to the will of the user even when the vehicle is travelling without detracting from convenience.